ASHINGTON - Cardinal William Keeler of Baltimore publicly apologized yesterday for mishandling cases of sexual abuse by priests in his archdiocese and said he regretted his decision in 1993 to return the Rev. Maurice Blackwell to his parish in spite of a teenager's credible accusations that the priest repeatedly had fondled him.

During a Mass at Baltimore's basilica yesterday, Keeler apologized to Dontee Stokes, now 26, and expressed sympathy to Stokes and his family.

A judge yesterday set bail at $150,000 for Stokes, who is charged with attempted murder and assault for shooting Blackwell outside his home Monday.

''I take this occasion to express publicly my apologies to all who have been victims and in a very special way to Mr. Stokes, who has suffered intensely because of the difficulties in which he now finds himself and in which we find ourselves,'' Keeler said.

In an opinion piece published in yesterday's Baltimore Sun, Keeler called the shooting ''the tragic fallout from sexual abuse issues'' and acknowledged that the city's Roman Catholic archdiocese had mishandled Stokes's allegations, contributing to ''painful breaches of trust.''

''I take full responsibility for the decision I made in 1993 given the facts and circumstances before me; in light of what has occurred and of what was revealed in 1998, I would not make the same decision today,'' Keeler wrote.

In 1998, Blackwell admitted to a homosexual relationship that ended in 1978, before he was ordained. Keeler lifted his privileges as a priest and removed him from St. Edward's Church. Blackwell, who was shot three times and remained hospitalized yesterday in fair condition, now directs an interfaith program for drug addicts.

P. McEvoy Cromwell, chairman of an independent lay board that has reviewed sexual abuse cases for Baltimore's archdiocese since 1993, said Keeler's apology was ''healthy and constructive.''

''Like the rest of us, the cardinal is increasingly focused on how horrible this thing is for the victims and what a terrible legacy it leaves long after the abuse has stopped,'' said Cromwell, who met with Keeler on Wednesday.

In 1994, the review board sharply disagreed with Keeler's decision to return Blackwell to his parish after a three-month stay at a Connecticut mental-health center and on the basis of a confidential medical report that said he was not a pedophile. In a letter, the board concluded that Stokes's allegations were consistent and credible, and that reinstating Blackwell at St. Edward's was an ''unacceptable risk.''

Cromwell, who has chaired the board since 1993, said the Stokes case illustrated the tension between the board, which supports a zero-tolerance policy on sexual abuse, and the archdiocese, which has ''favored a more flexible, less spartan result.'' The board, which until April had reviewed 64 sexual abuse cases over nine years, cannot veto a decision by the archdiocese but ''we do have the power to look over their shoulder and holler if we don't like a result,'' Cromwell said.

Keeler said the shooting ''underscored how grave the issue is for our community.'' In fact, Cromwell said, the archdiocese has seen a ''dramatic increase'' of about two dozen new allegations of abuse in the last two months. He attributed it to people feeling less afraid to come forward.

''We have no confusion among us that we must put first the safety of children, followed closely by outreach and pastoral care for the victims,'' wrote Keeler, who heads the oldest Roman Catholic archdiocese in the country and was named its archbishop in 1989.

At a bail hearing, Dr. Steven Siebert testified that he had interviewed Stokes and found him ''coherent ... praying for his recovery ... and remorseful.'' The judge ordered Stokes to remain under house arrest and to be fitted with an electronic monitoring device.